When a pipe is to be installed under a finished surface such as a driveway or street, it is a routine procedure to provide operating and target trenches on the opposite sides of the finished surface. The pipe installing device generally replaces the bucket on a standard tractor-mounted hydraulic backhoe and the device is properly located and braced in the operating trench for the rod pushing operation. A first rod length is inserted through a pair of drive jaws in the device and drivingly engage thereby to push said first rod length under the finished surface. The trailing end of the first rod length is provided with a coupling to receive a second rod length whereupon the hydraulic drive means of the tractor is reactivated to push the second rod length forwardly under the finished surface toward the target trench. A sufficient plurality of rod lengths are similarly coupled to proceeding rods until the leading tip end of the first rod length emerges into the target trench.
The leading tip end is threadably provided with a pusher cap which is removed therefrom in the target trench and replaced by an adaptor for connection to the leading end of a pipe to be permanently installed under the above surface; said pipe being so installed by reconditioning the bracing means and drive jaws to reverse the direction of movement to pull the pipe back through the hole formed by the rod until the leading end thereof, coupled to the rod, emerges into the operating trench.
The above described operations are quite conventional, however difficulties are often encountered with such conventional devices because the rod or pipe is not accurately guided by the pusher device. For example, various obstructions such as rocks are sometimes encountered causing a deflection in the direction of movement of the rod, until it pushes out of the conventional guides of the device. Devices of this type are often used to install underground pipes for distances up to several hundred feet and a slight initial deflection of the rod is magnified tremendously over such long distances.
The pipe guide means of the present invention provides a plurality of front and back guide rollers, applicable to various underground pipe installing devices, which provide for a more accurate pipe installation job.